Nanomaterials have attracted a significant amount of scientific attention due to their unique properties. Because of these unique properties, nanoparticles are used in applications related to opto-electronics (such as light emitting devices and solar cells), medicine (such as drug delivery vehicles and diagnostic devices), energy storage, and environmental technologies (such as water purification).
Storage and handling of nanomaterials remains a major challenge due to the inherent instability of these materials. Due to the high surface to volume ratio, high surface reactivity, and other effects governing small particles such as Ostwald ripening, nanoparticle suspensions are prone to form aggregates and destabilize shortly after synthesis. A common solution to this problem is to add surfactants or stabilizing agents. High sensitivity of the stabilizing agents to temperature, pH and electrostatic effects make the storage and handling of nanoparticles complex and costly.
Addition of surfactants or stabilizers that modify the surface of the nanoparticles has major implications for the end application as well. For example, nanoparticles used for biomedical imaging or drug delivery applications often need to be functionalized in order to bind to specific target molecules or cells. These surfactants or capping agents can prevent or complicate the required surface functionalization. Another application area for nanoparticles is in opto-electronics. Capping agents and surfactants used during synthesis or as stabilizing agents, block or highly restrict the flow of electric charges across the particle boundaries. Complex post treatment processes, such as ligand exchange, are often necessary to impart the required electrical and optical properties to the nanoparticles in order to use them in light emitting devices and solar panels.
Therefore, it is desirable to develop a scalable, inexpensive, and environmentally-friendly method for long-term storage and on-demand release of nanoparticles without relying on the use of any additives.
This section provides background information related to the present disclosure which is not necessarily prior art.